Advanced reproductive technologies (ART) such as in vitro fertilization have radically improved since the late 1960s and have become increasingly common. The implicit assumption behind widespread use of ART has been that children born through ART use are similar to other children. Using variation provided by state mandates to insurers to cover infertility treatment, this research will test this assumption by estimating the demographic and health effects of ART use. This proposal's specific aims are to: (1) seek direct evidence about how common ART use is, the characteristics of women using ART, and how utilization is related to state laws mandating that insurers cover infertility treatment, using data from the National Survey of Family Growth (NSFG); (2) investigate the impacts of ART use and of state-mandated insurance coverage of infertility treatment on the number of births, maternal age at birth, and the incidence of multiple births, using both the NSFG and Vital Statistics birth certificate data; and (3) analyze the impacts of state-mandated insurance coverage of infertility treatment on birth weight, gestation, and infant mortality using Vital Statistics birth certificate data. This final specific aim is the core of this proposal and has important implications for the ongoing debate about birth selection in demography and health economics. ART and its demographic and health impacts are of interest. Further, ART generates an archetypal birth-selection problem, altering the infant health distribution not by affecting the health of a fixed infant population but by making it possible for a new subset of children to be born. Such birth selection raises important methodological and conceptual issues, which this work will address. This research faces a further methodological challenge: births through use of ART are a tiny share of all births, so sample sizes are likely to be quite small. However, preliminary studies have shown ART impacts can be clearly seen among twin births, especially among twins born to older mothers. This research will extend these preliminary studies to look at all births, and to look at additional outcomes such as infant mortality. [unreadable] [unreadable]